Existing methods for managing the variations in gain due to the temperature dependence in so-called silicon photomultiplier (SiPM) and avalanche photo detector (APD) devices typically include one or more microprocessors. In some situations, a temperature sensor is included for read out by the microprocessor(s) which in turn actively controls either the bias supply or a variable gain amplifier stage.
In systems where a large number of devices require compensation the approaches using such microprocessor control are not practical. In these larger systems the problems with implementing tight gain matching in temperature become difficult and costly with the active compensation approaches. Complicating matters the photodetectors are unlikely to all be at the same temperature, so any small number of temperature sensors may not sufficiently sample the photodetector temperatures. Additionally, the higher power requirement and thermal load of a multiplicity of active temperature sensors and the associated bias control circuitry may exceed the power available or contribute to the thermal load further exacerbating the problem.
Accordingly, what is needed is a simpler and less costly device and method for managing the variations in gain due to the temperature dependence in silicon photomultiplier (SiPM) and avalanche photo detector (APD) devices.